Pontoon boat



(I 1966 G. F. THOMPSON 9 PONTOON BOAT Filed Feb. 15, 1965 INVENTOR.

GEORGEE THOMPSON norws tawl g E, Affomveu s United States Patent M ware Filed Feb. 15, 1965, Ser. No. 432,680 2 Claims. (Cl. 9-1) This invention relates to a pontoon boat of the catamaran type having pontoons laterally spaced apart and supporting a substantially flat deck structure.

The invention is more particularly related to the arrangement of an outboard drive on such a boat whereby a single outboard motor disposed centrally of the stern will be eflicient in driving the boat at relatively high speeds where there may be some tendency for the 'water to become aerated in the region approaching the propeller.

In carrying out the invention the outboard drive is disposed a reasonable distance rearwardly from the stern of the pontoons and with its propeller disposed to the rear and beneath a tapered runner which reduces any tendency toward cavitation in the region of the propeller.

The runner tapers forwardly and upwardly to merge with the bottom of the boat deck at a position just forward of the pilot so that the pilot controls may extend downwardly through the deck into the runner and then rearwardly through the runner to the outboard motor,

leaving the deck free from any obstruction by the controls.

An adjustable plate is secured at the rear end of the runner to fit different motors and maintain the desired anticavitation effect for the propeller.

The runner extends a distance rearwardly of the deck and pontoons to provide a space for accommodating the engine upon tilt-up of the motor without interference by the deck, and to provide better steering control for the boat.

The maximum depth of the runner is substantially less than the depth of the pontoons to compensate for the rise in the water level behind the boat and any tilting of the boat at higher speeds. The pontoons generally ride lower in the water than would be desired for the propeller of the outboard motor.

The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.

In the drawings:

FIGURE 1 is a side elevation of a boat with an outboar motor mounted thereon;

FIG. 2 is an enlarged top plan view of the stern portion of the boat with the motor partially broken away to show the runner fit thereto;

FIG. 3 is a rear elevation of the boat with the motor removed; and

FIG. 4 is an enlarged perspective view of the runner prior to its attachment to the bottom of the boat.

The boat comprises, in general, a flat deck 1 supported on two side pontoons 2 and 3 and having a pilot stand 4 centrally near the stern.

A suitable railing 5 or other suitable protective enclosure extends around the deck to prevent people and objects from falling overboard.

The boat is powered by a single outboard motor 6 which is mounted on a transom 7 at the rear end of a runner 8.

The runner 8 comprises a hollow channel member facing upwardly with the upper edges of its side walls 9 flanged outwardly as at 10 and secured to the underside of deck 1 preferably by welding.

The runner 8 is tapered forwardly by having its bottom web 11 inclined from a maximum depth at the rear end of the runner to a point 12 of merger with the deck 3,289,226 Patented Dec. 6, 1966 1 at the forward end of the runner just ahead of the pilot stand 4.

The transom 7 comprises a heavy wooden plank extending transversley of the channel runner between the side walls 9 and which is held in place by suitable angle irons 12 secured to the corresponding side walls. The transom 7 generally tilts rearwardly from a vertical plane to simulate boat transoms for attachment thereto of the outboard motor.

The transom 7 preferably does not extend down to web 11 and the space thus provided therebetween serves to drain water that may enter the runner over the top thereof. The angle irons 12 likewise preferably do not extend down to web 11, but allow suflicient clearance to accommodate an adjustable anti-cavitation plate 13 which is fastened upon the web 11 and extends rearwardly toward the outboard motor to prevent upward swelling of water between runner 8 and the outboard motor.

The plate 13 preferably has a notch 14 centrally of its rear edge to accommodate the nose of the housing of the outboard motor. Similarly web 11 has a notch 15 centrally of its rear end edge to receive the housing of the outboard motor.

The notch 15 is substantially larger than notch 14, and depending upon the position of the outboard motor the adjustment of .plate 13 will effect a partial or a complete covering of notch 15 by the plate 13.

The plate 13 is secured on web 11 by means of suitable bolts 16 which fit in holes in web 11 and extend through the adjustment slots 17 in the plate.

The runner 8 is open at the top in the region between deck 1 and transom 7 and will receive the front portion of the engine cowl in the event of a severe kick-up of the outboard motor as when striking an underwater obstruction at high speed.

The control connections for steering, throttle regulation and clutch shifting extend downwardly from pilot stand 4 through deck 1 and inside runner 8 to the front of the outboard motor as shown in dotted outline in FIG. 1.

The maximum depth of runner 8 corresponds to the desired depth for the anti-cavitation plate 18 on the outboard motor so that the two anti-cavitation plates 13 and 18 are generally at the same level. In general this depth of runner 8 will be substantially less than the depth of pontoons 2 and 3 which support the weight of the boat and motor in the water.

By mounting the outboard at a ditsance rearwardly of the deck 1 and pontoons 2 and 3, an improved steering relation is provided between the outboard motor and the boat, and at the same time the tilt movement of the motor is accommodated as previously described.

By terminating the forward end of runner 8 at a point near the pilot stand and not extending it to the bow of the boat, a softer ride is obtained particularly at semiplaning speeds.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention:

I claim:

1. In combination in a pontoon boat of the catamaran type having a deck and a pair of laterally spaced side pontoons supporting the deck above the water, a central runner secured beneath the deck and extending rearwardly thereof and of said side pontoons, said runner comprising an upwardly facing hollow channel member with its botom web inclined upwardly to merge with said deck at its forward end, a transom disposed across said channel member at its rear end and adapted to mount an outboard motor at a position substantially spaced 3 4 rearwa rdly from the boat, and anti-cavitation means exto expose a selected amount of said notch and thereby tending rearwardly of said transom toward the outboard accommodate adjustment of the outboard motor.

motor to a position closely adjacent the motor to prevent swelling of the water between the runner and the out References Cited by the Exammer board motor. 5 UNITED STATES PATENTS 2. The construction of claim 1 in which said anti- 2,950,699 8/ 1960 Ogden et a1 1l46l cavitation means comprises a plate secured to the bottom 3,210,783 10/ 1965 Petty 91 web of said runner and the latter is cutaway to provide a notch for receiving the housing of the outboard motor, MILTQN BUCHLER P "1mm? Examinerand means adjustably securing said plate fore and aft 10 T, M BLIX, Assistant Examiner. 

1. IN COMBINATION IN A PONTOON BOAT OF THE CATAMARAN TYPE HAVING A DECK AND A PAIR OF LATERALLY SPACED SIDE PONTOONS SUPPORTING THE DECK ABOVE THE WATER, A CENTRAL RUNNER SECURED BENEATH THE DECK AND EXTENDING REARWARDLY THEREOF AND OF SAID SIDE PONTOONS, SAID RUNNER COMPRISING AN UPWARDLY FACING HOLLOW CHANNEL MEMBER WITH ITS BOTOM WEB INCLINED UPWARDLY TO MERGE WITH SAID DECK AT ITS FORWARD END, A TRANSOM DISPOSED ACROSS SAID CHANNEL MEMBER AT ITS REAR END AND ADAPTED TO MOUNT AN OUTBOARD MOTOR AT A POSITION SUBSTANTIALLY SPACED REARWARDLY FROM THE BOAT, AND ANTI-CAVITATION MEANS EXTENDING REARWARDLY OF SAID TRANSOM TOWARD THE OUTBOARD MOTOR TO A POSITION CLOSELY ADJACENT THE MOTOR TO PREVENT SWELLING OF THE WATER BETWEEN THE RUNNER AND THE OUTBOARD MOTOR. 